Histamine and Heavy Metals Content of Canned Tuna Fish

Tuna is able to concentrate large amount of heavy metals and contain high levels of free histidine in their muscles which can convert to histamine. In this study, the levels of histamine and six heavy metals in canned tuna fish samples were determined. The histamine content of the samples was observed to be in the range of 4-236 mg/kg and 18.9 % of the samples contained more than 50 mg/kg, the allowable limit suggested by US FDA. The contents of investigated heavy metals were found to be in the range of 0.007-0.51 ^g/g for lead, 0.002-0.07 ^g/g for cadmium, 0.023-13.108 ^g/g for tin, 0.17-8.001 ^g/g for copper, 0.124-27.001 ^g/g for zinc and 0.009-14.207 ^g/g for iron. The results of this study indicate that the average content of histamine in canned tuna fish marketed in Iran was lower than the allowable limit suggested by FDA. Results achieved for heavy metals were in good agreement with other reported data from the literature.